Results 21 - 30 of 32

• Interaction of Radio Transmissions on Mine Monitoring and Control Systems
  9/1/1986 - Contract reports
  This report describes the creation of an efficient method to determine if command, control, communication, and monitoring (3cm) equipment in coal, metal, and nonmetal mines is susceptible to radio frequency interference (RFI) from the medium-frequency (...
• A Medium Frequency Wireless Communication System for Underground Mines
  9/1/1984 - Contract reports, Open File Reports
  This report deals with information regarding a new Medium Frequency (MF) Wireless Communication System for underground mines. This new telecommunication system works on low loss electromagnetic wave propagation modes which allow it to provide quality ra...
• A Medium Frequency Wireless Communication System For Underground Mines
  1/1/1983 - Contract reports
  An underground medium frequency radio communications system has been developed and demonstrated in both coal and metal/non metal mines. The principal advantage of the system are its low cost, ease of installation and the ability to provide radio communi...
• A Whole-Mine Medium-Frequency Radio Communication System
  7/1/1982 - Conference papers
  A medium-frequency (MF) communication system has been built and has been tested in underground mines. It provides radio coverage to vehicles and personnel anywhere in the mine via parasitic coupling into existing mine conductors.
• The Implementation of UHF Radio Communications and CCTV Monitoring Systems in a Room and Pillar Metal/Non-metal Mine
  3/1/1981 - Contract reports
  This report describes the design and implementation of UHF radio and closed-circuit television systems in the Black River room and pillar limestone mine near Butler, Pendleton County, Kentucky.
• Propagation of EM Signals in Underground Metal/Non-Metal Mines
  1/1/1981 - Contract reports
  This report describes the results of a measurement and analysis program to characterize wireless radio transmission in metal-nonmetal mines over a wide frequency range from 0.2 to 1,000 mhz and over a variety of mine environments.
• Wireless Communications for Trackless Haulage Vehicles
  7/1/1979 - Contract reports, Open File Reports
  This report describes a complete system design for medium frequency ( MF) wireless radio systems for use in coal mines. The emphasis is on AC mines where no trolley wire exists and, for which, conventional trolley phone communications cannot be used. Th...
• Propagation of UHF Radio Waves in Limestone Room and Pillar Mines
  1/1/1979 - Contract reports
  This report presents a mathematical model for the propagation of UHF radio waves in the large cross section tunnels of a room-and-pillar limestone mine and describes the analysis of a small amount of propagation data obtained. The model and analysis is ...
• Development of a Call Alert System for Paging Mine Personnel
  1/1/1978 - Contract reports
  This report presents system objectives and design criteria for an in-mine ultralow frequency radio paging system.
• Transmit Antennas for Portable VLF to MF Wireless Mine Communications
  9/1/1977 - Contract reports
  An investigation was made of the feasibility of developing compact transmit antennas and/or other means to efficiently couple VLF to MF band radio energy between portable wireless communication units in coal mines. The completely wireless communication ...